Double plate rectifier



Aug" 2, 1932.

, c. A. HG N DOUBLE PLATE R'EcTfFIER Original Filed Jan. '25, 1928 MIN HHHHH INVENTOR 1/1/95/1/(5 fl //0/?/V BY W ATTORNEY Patented Aug. 2, 1932 UNITED STATES PATENT 'OFFEOE CLARENCE A.HORN; OF BAHWAY, NEW JERSEY, ASSIGNOR TO ARCTURUS RADIO TUBE COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF DELAWARE DOUBLE PLATE nnc'rirrna 7 ,Application filed January 25, 1928, Serial no. 249,257. Renewed May 15, 1930.

i This invention relates to vacuum rectifier tubes used for rectifying alternating current and is an improvement over the tube shown in the application of Walter Louis Krahl en- 210,809, filed: August 5, 1927.

One of the objects of the invention is to provide a full wave rectifier tube, which will uniformly rectify both sides of the alternat v ing current wave.

Another object of the invention is to provide a full wave rectifier tube having a single cathode which has relatively little loss of electron emission.

Another object of the invention is to provide a full wave rectifier tube which is easy to assemble and comprises a minimumof elements.

' Other objects of the invention relating par ticularly to economies of manufacture will be apparent as the description thereof proceeds.

One embodiment of the invention has been illustrated in the'accompanying drawing, in

V which Fig. 1 is a perspective view partly in section of a-tube embodying the invention; and "Fig. 2 is the circuit diagram indicating the manner in which the tube may be connected in a circuit.

In the application for Full wave rectifier above referred to, a single cathode is employed-with two plates each comprising half of a cylinder, the two plates being'spaced 5 from the cathode and from each other sothat a narrow opening is formed on each side of the cathode between the edges of the plates and through which electron emission may pass toward the walls of the envelope where it is entirely wasted. The present invention is adapted to eliminate this waste of electron emission by completely surrounding the oathode with the two plates so that no space will be left through which the electrons may pass.

Also, in the said application above referred to, the plates, being semi-cylindrical and spaced one on each side of the cathode, must be exactly the same distance from the cathode in order to receive equal current therefrom,

and it is very difficult to so space the plates titled, Full wave reotifieri, Serial No.

within certain limits, with respect to the cathode.

The invention is shown as comprising an envelope 10 having the usual base 11 which supports the terminals for making the various connections in the circuit. A press 12 is positioned inside of the envelope 10 and supports the elements of the tube. These elements comprise a cathode 13, a heater 14C for energizing the cathode and a pair of plates or anodes 15 and 16. The cathode 13 is supported at its lower end upon the conductor 17 which is sealed in the press 12 and which is connected to the lower end o'f'the cathode by a strip 18 which surrounds the same and is welded to the conductor 17. V The upper end of the cathode may be supported by a con ductor 19 which is sealed in the press 12 and which is bent outwardly and upwardly to a point adjacent the top of theenvelope and which may have welded to it near the upper end thereof a strip 20 which surrounds the upper end of the cathode. The filament 145 may be supported at its lower end by means of the conductor21 which is'also sealed in the press 12, and the upper end of the filament may be supported upon the conductor 19 by means of a spring 22 which is welded to the conductor 19 and is maintained under tension to compensate for variations in length ofthe filament due to temperature changes and keeps the filament taut and separated from the walls of the cathode. The plates 15 and 16 are formed of strips of metal bent in the form of cylinders, the ends of the strips being bent outwardly to form flanges 23 and 2 1-, the outer ends of which may be dished or grooved to form sockets for receiving the conductors which separate the plates.

The plate 15 is mounted concentrically with the cathode adjacent the upper half thereof and is supported by the conductor 25 which is sealed in the press 12 and extends upwardly engaging the socket formed in the flange 23. The plate 16 ispositioned around and concentric with the lower hali oi the cathode and is supported upon the conductor 26 which is also sealed in the press 12.

In order to space the upper ends of the plates 15 and 16 1 preferably use a glass head 27 which is supported upon the upright 1%). A support rod 28 may be sealed in one end or the glass bead 2'7 and may extend upwardly and inwardly above the iiange ot' the plate 15 and then may be bent downwardly to engage the socket therein while a second rod 29 may be sealed in the other end 01 the glass bead 2? and may in like manner, extend upwardly and inwardly to a point above the fiange2a on the plate 16 when it is bent downwardly to engage the socket formed therein. this means both plates 15 and 16 are rigidly supported at the upper and lower ends of the cathode respectively and are spaced and insulated from each other.

In the operation of the tube, if the two cylindrical plates are exactly the same diameter the electron emission to both of these plates will be equal, irrespective of whether or not the plates are exactly concentric with respect to the cathode. Thus the rectification of both sides of the alternating current wave will be uniform in spite of slight manufacturing displacements in the positioning of the plates.

The lower end of the filament is connected through the support 21 by means of a wire 30 to the filament terminal 31 at the base of the tube, while the upper end of the filament and the cathode are connected through the support 19 and wire 32 to the other heater terminal 33 at the base of the tube. The rod 17 supporting the lower end of the cathode may also be connected to the wire 32 so that the potential of the cathode is substantially uniform throughout its length. The plate 15 may be connected through the support 25 and wire 34 to the terminal 35 at the base of the tube While the plate 16 may be connected throughthe conductor 26 and wire 36 to the other plate terminal 37 at the base of the tube.

A conventional circuit in which the tube may be used is illustrated in Fig. 2. A transformer 38 is shown having a primary winding 39 which is adapted to be connected across an alternating current ower line while the secondary is divided into two coils 4:0 and 41, the latter being connected directly to the filament terminals 31 and 33 of the tube by wires 42 and 43 respectively and forming the source of the heater current, and the former having its ends connected to plate terminals 35 and 37 by means of wires 44 and 45 respectively. The load 16 and a filter 47, if desired, may be connected in series between the heater terminal 33 to which the cathode is attached and substantially the mid point 48 of the secondary coil 40.

The cathode 13 should preferably be coated only on that part of the surface thereof which is surrounded by the plates 15 and 16 so that no electron emission is wasted above and below either or the plates.

It will be evident from the above that I have provided a full wave rectifier which is simple in construction, easy to assemble and which will intercept all or the electron emission lfl'OlIl the cathode of thetube, and give uniform rectification to both sides of the alternating current wave.

While I have described and illustrated one embodiment of the invention, I do not desire to limit myself to the specific construction shown and described, as various changes may be made in the design thereof without departing from the spirit of the invention, but I desire to interpret the invention broadly, limited only by the scope of the appended claims.

What I claim is:

1. A full wave rectifier tube comprising a pair of cylindrical anodes longitudinally spaced from each other, means on one side of said anodes to support one of said anodes and means on the other side of said anodes to support the other of said anodes, a cylindrical cathode substantially concentrically disposed within said anodes and common to both said anodes a heater within said cathode and means supporting the upper ends of both said anodes and the upper end of said cathode in spaced relation.

2. A full wave rectifier tube comprising an envelope, a single press within said envelope, a cylindrical cathode mounted within said envelope and upon said press,a pair of cylindrical anodes longitudinally spaced apart and concentric with said cathode, means on one side of said anodes to rigidly support the lower end oi one of said anodes, means on the other side of said anodes to rigidly support the lower end of the other of said anodes, a support sealed in the press of said tube and extending longitudinally of said anodes and spaced therefrom, means to support the upper end of said cathode from said longitudinally extending support, and means to insulatingly support the upper end of each of said anodes from said longitudinally extending support.

3. A full wave rectifier tube comprising a cylindrical cathode, a single press, a support for the lower end of said cathode sealed in said press, a second support sealed in said press and extending longitudinally of said cathode but spaced therefrom, a member rigidly connecting the upper end of said cathode withsaid second support, a pair of anodes substantially concentrically mounted with respect to said cathode and longitudinally spaced therearound, means to support the lower ends of each of said cathodes from said press, an insulating member sealed to said second support, means rigidly connecting the upper end of one of said anodes to said insulating member, and means rigidly connecting the upper end of the other of said anodes to said insulating member, whereby said cathode and anode are rigidly supported in spaced relation With each other.

In testimony whereof I affix my signature.

CLARENCE A. HORN. 

